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BUG: KASAN: slab-out-of-bounds in nexthop_is_blackhole+0x268/0x2c0 include/net/nexthop.h:372
Read of size 1 at addr ffff88806663ad1e by task kworker/0:5/5886

CPU: 0 UID: 0 PID: 5886 Comm: kworker/0:5 Not tainted 6.15.0-syzkaller-gdf3bed9ea576 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: mld mld_ifc_work
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 nexthop_is_blackhole+0x268/0x2c0 include/net/nexthop.h:372
 __find_rr_leaf+0x428/0x6d0 net/ipv6/route.c:855
 find_rr_leaf net/ipv6/route.c:899 [inline]
 rt6_select net/ipv6/route.c:934 [inline]
 fib6_table_lookup+0x53f/0xa80 net/ipv6/route.c:2232
 ip6_pol_route+0x222/0x1180 net/ipv6/route.c:2268
 pol_lookup_func include/net/ip6_fib.h:617 [inline]
 fib6_rule_lookup+0x52f/0x6f0 net/ipv6/fib6_rules.c:120
 ip6_route_input_lookup net/ipv6/route.c:2337 [inline]
 ip6_route_input+0x6ce/0xa50 net/ipv6/route.c:2640
 ip6_rcv_finish+0x141/0x2d0 net/ipv6/ip6_input.c:77
 NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:317
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0xd3/0x380 net/core/dev.c:6090
 process_backlog+0x60e/0x14f0 net/core/dev.c:6442
 __napi_poll+0xc7/0x480 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x707/0xe30 net/core/dev.c:7605
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 do_softirq+0xec/0x180 kernel/softirq.c:480
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline]
 __dev_queue_xmit+0x1cd7/0x3a70 net/core/dev.c:4740
 neigh_output include/net/neighbour.h:539 [inline]
 ip6_finish_output2+0x11fb/0x16a0 net/ipv6/ip6_output.c:141
 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]
 ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:226
 NF_HOOK+0x9e/0x380 include/linux/netfilter.h:317
 mld_sendpack+0x800/0xd80 net/ipv6/mcast.c:1868
 mld_send_cr net/ipv6/mcast.c:2169 [inline]
 mld_ifc_work+0x835/0xde0 net/ipv6/mcast.c:2702
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 10486:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4358
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 binderfs_binder_device_create+0x1eb/0xc40 drivers/android/binderfs.c:147
 binderfs_fill_super+0xa0e/0xe90 drivers/android/binderfs.c:730
 vfs_get_super fs/super.c:1323 [inline]
 get_tree_nodev+0xb8/0x150 fs/super.c:1342
 vfs_get_tree+0x92/0x2b0 fs/super.c:1802
 do_new_mount+0x24a/0xa40 fs/namespace.c:3856
 do_mount fs/namespace.c:4193 [inline]
 __do_sys_mount fs/namespace.c:4404 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4381
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88806663ac00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 6 bytes to the right of
 allocated 280-byte region [ffff88806663ac00, ffff88806663ad18)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88806663a800 pfn:0x66638
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88801a441c80 ffffea00016e4110 ffffea00016bbf10
raw: ffff88806663a800 000000000010000e 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801a441c80 ffffea00016e4110 ffffea00016bbf10
head: ffff88806663a800 000000000010000e 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0001998e01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 10077, tgid 10077 (syz-executor), ts 350373821948, free_ts 318923274477
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2618
 new_slab mm/slub.c:2672 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858
 __slab_alloc mm/slub.c:3948 [inline]
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x142/0x860 net/ipv6/route.c:3764
 ip6_route_add+0x28/0x190 net/ipv6/route.c:3889
 addrconf_prefix_route net/ipv6/addrconf.c:2487 [inline]
 fixup_permanent_addr net/ipv6/addrconf.c:3602 [inline]
 addrconf_permanent_addr+0x67f/0x9d0 net/ipv6/addrconf.c:3626
 addrconf_notify+0x887/0x1010 net/ipv6/addrconf.c:3698
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
 call_netdevice_notifiers net/core/dev.c:2282 [inline]
 __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1
 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9526
 do_setlink+0xc55/0x41c0 net/core/rtnetlink.c:3141
page last free pid 4586 tgid 4586 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
 __folio_put+0x21b/0x2c0 mm/swap.c:112
 folio_put include/linux/mm.h:1356 [inline]
 free_large_kmalloc+0x145/0x200 mm/slub.c:4767
 rate_control_free_sta net/mac80211/rate.h:52 [inline]
 sta_info_free+0x577/0x660 net/mac80211/sta_info.c:434
 sta_info_insert_finish net/mac80211/sta_info.c:939 [inline]
 sta_info_insert_rcu+0x83c/0x1940 net/mac80211/sta_info.c:960
 ieee80211_ibss_finish_sta+0x293/0x380 net/mac80211/ibss.c:568
 ieee80211_ibss_work+0x221/0x1060 net/mac80211/ibss.c:1654
 cfg80211_wiphy_work+0x2df/0x460 net/wireless/core.c:435
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88806663ac00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88806663ac80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88806663ad00: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
                            ^
 ffff88806663ad80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88806663ae00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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